In SX Microcontrollers, SX/B Compiler and SX-Key Tool, gtslabs wrote:

I ordred 4 Thumbwheel switches today, 0-9 BCD output that I plan on getting a value from 0 to 9999 from.
I wrote some code to read the condition of the inputs on SX48 RB.D and RB.E I have not tested it yet but it compiles ok.

 

I am looking for some schematics for wiring up these Thumbwheel switches. The Datasheets mainly give the truth tables and not much on other info like pullup resistors or diodes if needed.

Thanks in advance

 



[code]

DEVICE          SX48, OSC4MHZ
FREQ            4_000_000 

Thumbwheel_12      Var       RD     ' 8 Input pins for ones and tens places
Thumbwheel_34      Var       RE     ' 8 Input pins for hundreds and thousands places 

  

ones        Var Byte
Tens        Var Byte
Hundreds    Var Word
Thousands   Var Byte
Total       Var Word 

  

PROGRAM Start
Start:
Main: 

  

Ones = Thumbwheel_12 & $0F 'Get lower 4 bits of RD 

  

Tens = Thumbwheel_12 & $F0 'Get Higher 4 bits of RD
Tens= Tens>>4    
Tens = Tens*10 

  

Hundreds = Thumbwheel_34 & $0F 'Get lower 4 bits of RE
Hundreds = Hundreds * 100 

  

Thousands = Thumbwheel_34 & $F0 'Get Higher 4 bits of RE
Thousands= Thousands>>4  

  

Total = Thousands*1000
Total = Total+Hundreds
Total = Total+ Tens
Total = Total+Ones 

GOTO Main 
[/code]

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